Why Custom Tank Heads Score Over Standard Ones

By Sam Ibrahim Jr

Overview and uses

A tank head is a formed piece of metal that is used for firmly securing the open end of a tank to prevent spills and leaks. Such heads are also required to be used on regular or pressurized vessels. In some industries, these are referred to as 'vessel heads'. There are several desirable attributes expected from a vessel head; these include sturdiness, high tolerances, uniform material thicknesses, and a perfect fit.

This particular component could be used on an autoclave, on vehicles that transport fuels and other fluids, chemical processing vessels, or on regular underground or aboveground water tanks.

Manufacturing tank heads

Tank heads can be manufactured in a variety of shapes such as circular, curved, and elliptical, with flanges. In most cases, an off-the-shelf approach doesn't work well for these vital components. Experts recommend that procuring a custom head for the tank is the best way to ensure a secure fit and the desired quality. A firm that specializes in custom fabrication and forming services can be contacted for these requirements. Such Companies have a full-fledged set-up where the most complex vessel head requirements can be honored.

Popular forming methods

Heads for tanks are usually made from a single sheet of metal. Welding different components to form a head for a tank could cause it to crack at the seams, and lead to leaks or spillage. The best way to form sheet metal for this component is through the use of methods such as hydroforming and metal spinning. These methods are also recommended when heads with tight tolerances are needed.

Here are some other reasons why spinning and hydroforming are the preferred methods for forming such heads for vessels and tanks:

• Advanced hydroforming and spinning methods can be used for creating regular heads that require a diameter of up to 15" and a depth of up to 10".


• These methods are also suitable when larger heads with a diameter of up to 72" are required.


• Various metals such as aluminum, steel, and stainless steel can be used for making a head for the desired vessel/tank.


• Manufacturing tank heads with uniform thickness is important to ensure that they do not deform or crack under pressure.


• Hydroforming and metal spinning are known to protect the integrity of the metal even as it is being formed.

Once the head component of the tank has been manufactured, it can either be bolted or welded to the tank or vessel. Alternatively, rivets can be provided on the tank for a secure fit. When placing an order, it is vital to ensure that your chosen firm adheres to standards such as ASME. Thus, it is evident that customized tank heads are a decidedly superior option to standard components from the quality and functionality standpoint.

Author is a writer and metal spinning industry expert, Author provided innovative design ideas, precision engineering services like metal rolling,rolled cylinders hydroforming, Spun Metal and deep drawing and metal spinning, to various Industries.

Eddy Current Testing - Inspection Methods Using Eddy Current Technique

By Zul S Sadiq

Eddy Current Testing (ECT) or Eddy Current Technique as it's known was developed to test nonferrous metals originally. Development has been made to allow the testing of ferrous metals via Mag-Wave technology as well as automated scanning, and high speed probe mechanisms.

Eddy current technique has many applications from the inspection of condensers, to feedwater heaters, coolers, evaporators and chillers to name a few. It's utilised across a wide range of industries from chemical, to petroleum to power and offshore.

Some common scenarios involve the following equipment and technology, and showcase some of the new innovations within the industry.

ECT Tubular Inspection - This can be performed using a TX-4400, which features 8 standard channels with a multiple of mixing channels, a 1KHz to 1.2MHz frequency range, real time mixing, and a wide variety of data filters. It's compatible with bobbin, surface and magnetic saturation probes. It's main benefits include four frequencies for better flaw detection and sizing, automated and manual modes, signal suppression of unwanted signals, and the ability to deliver reports onsite via TS-MAP and AR-Wizard.

The second new application is a form of high speed inspection utilising the PD-6K. It's lightweight and fast. It connects to the TX-4400 and inserts probes quickly. It has the ability to adapt to different air fittings and only requires plant air. It's obvious benefit is it's speed, with speeds up to 5ft/second (1.52m/sec) achievable. It can inspect up to 8 tubes/minute and 2-3k tubes per team per 12 hour shift and can be used on ferrous or non-ferrous materials.

In follow up to the above technology, 'Ultra High Speed Inspection' was developed to produce even faster speeds. The piece of kit involved is called the PDP-22. Again it connects to the TX-4400 and can fit in a 16" (406mm) manway. It uses a modular design for easy repair, and holds probe inspection speeds constant. This kit can do inspection at speeds of 10ft/sec (3.05m/sec) and can inspect up to 12 tubes per minute, or 4-5k tubes per team per 12 hour shift.

The final technology involves the evolution to ferrous metals. 'Ferrous ECT Inspection' as it's known, and utilises the Mag-Wave ET (MWET) to test. MWET features a 1KHz to 500KHz frequency range, automated analysis, and automated insertion of probes. A variety of probe sizes are supported and connects to the TX4400 once again. The advantage of Mag-Wave is obviously the inspection of ferrous metals. Small pitting can be detected and quantified, large volume flaws can be detected and quantified, and saturation can be adjusted to eliminate signal noise due to finned tubes. It can also differentiate between ID (Internal Diameter) and OD (Outside Diameter) flaws.

As you can see the following technologies have different applications and uses, and have been largely developed to meet the changing needs various industries.

For more information on NDT or a recommended eddy current technique provider, visit TesTex NDT